Interactive Display

The TAFs page displays current surface observations. This page uses
OpenLayers to provide an interactive display of data including zoom and pan
and each observation can be clicked on to get more information.

Parameter Output

Here is a list of the parameters that can be displayed:

station model - This is a standard station model with visibility
far left, weather near left, cloud cover colored by flight category and wind
barb.

When the site is clicked, a dialog box appears with the latest raw TAF
data displayed. If the decoded option is set, decoded data for the requested
forecast hour will display in place of the TAF. If the metar option is set,
the latest METAR will be appended to the end of the data.

The data density setting changes the priority level of data to display.
Selecting “-1” will reduce the number of stations plotted. A “+1” will
roughly double the number. A “+2” will double again the number of plotted
stations. Select the density appropriate to the needed plot.

Station Model Plot

Figure 1: Station Model Plot

In many cases, the data are plotted using standard symbols and plotting
models. Fig. 1 shows the station model used in the METAR and TAF plots.

Ceil - Ceiling height in hundreds of feet. This represents the
height of the lowest broken or overcast cloud layer.

Id - The 4 letter ICAO identifier for the site. KRFD is Rockford
IL.

Windbarb - The wind barb. The stick points in the direction the
winds are coming from. Each full barb represents 10 knots of wind. Each
half barb represents 5 knots. Red represents wind gusts. In this case,
you have winds from the SSE at 25 knots with gusts to 30 knots.

Vis - The visibility plotted to the left of the weather symbol,
in statute miles (km for metric).

Wx - A symbol representing present weather plotted just to the left
of the cloud cover symbol.

Cover - The cloud cover symbol is plotted in the center. The amount
the circle is filled represents the amount of cloud cover. In this case, it's
overcast. The color of the circle represents the flight conditions:

Figure 2: Flight category icon color

green - VFR (Visual Flight Rules)

blue - MVFR (Marginal Visual Flight Rules)

red - IFR (Instrument Flight Rules)

purple - LIFR (Low Instrument Flight Rules)

URL Options

Here is a list of the URL options:

date=yyyymmddhhnn - This selects a specific date and time
to display. The ADDS database stores roughly a weeks worth of METAR data.
Selecting a specific date will display METARs valid for that time.

center=lat,lon - This will center the map at a specific
latitude and longitude. The default is 39,-97.

zoom=level - This sets the zoom level. The default is 4.
A higher number zooms in. A lower number zooms out.

basemap={light|dark|simple} - This selects the type of basemap.
The default is light.

sat={on|off} - This turns the satellite layer on or off. The
default is on.

radar={on|off} - This turns the radar layer on or off. The
default is on.

plottype=param - This selects the display parameter. The
default is model. Options are:

model - station model

vis - visibility

ceil - cloud ceiling

cover - cloud cover

wind - wind barb

wspd - wind speed

wgst - wind gust

cat - flight category

wx - weather symbol

type={prevail|tempo} - This selects the type of plot, either for
prevailing or temporary conditions. The default is prevail.

density={-1|0|+1|+2} - The data density. The greater the number
the more stations will plot. The default is 0.

metric={on|off} - Specifies to display data in metric units. The
default is off.

decoded={on|off} - Specifies to show decoded data in popup dialog
box. The default is off.